Self expanding stents are useful for a variety of procedures requiring the patency of a bodily pathway. Such stents are generally biased to expand, such that when deployed, they assume an open position, pushing outward and into the surrounding area into which deployed. The radial expansion creates a pathway in a once occluded area. However, once deployed, such stents become difficult to remove or reposition when no longer in a collapsed state due to the expandable nature of the stent. Merely pulling or pushing the stent while in an expanded state to reposition or remove it may cause damage, trauma, or destruction of the area in which the stent is placed.
Moreover, self expanding stents, when in an expanded state, generally have a length shorter than when in a collapsed state. This property, known as foreshortening, may result in a stent being deployed in the wrong position because the stent shortens during expansion. Accurate placement of the stent may be important in certain applications, for example to prevent stent migration or to properly open a stricture along the entire length of the stricture.